One of my 'audio only' systems (2 x M3s) suffered from ridiculous bass reinforcement due to their placement in corners. This was the case with any brand or model of speakers that I placed there so it is not just an M3 phenomena. To compensate, I had to EQ the bass down on my receiver from '0' to '-6' (out of 10) to try to tame the bloated bass response. It sounded quite good that way; however, I was concerned with what lowering the receiver's bass level was doing to the overall FR of the system.

Hmmmm, says me after watching Andrew's Port Plug explanation so I decided to experiment a little. Being a pack-rat, I found in my stash of 'stuff' in my workshop, some quite dense, but also flexible packing foam (1/2" thick) that had thin cardboard backing glued on. I easily cut with scissors a couple plugs a little bigger than the port diameter & press-fit them firmly into the ports.

I set the receiver back to 'flat' & played some quality CDs. What a difference - any remaining muddiness completely disappeared & overall sound balance morphed from good to superb. Higher volume levels are far more forgiving as well. Rest assured, there was no placebo effect here - the difference was dramatic.

This experiment was so successful, I just may purchase a couple of the 'official' plugs when they become available. Thanks to Axiom for this great tip...

I am wondering about doing this with my VP180. It sits below my plasma monitor on the middle shelf. Being a fellow pack-rat I am going to look around for some suitable material and see how it affects the 180.

1. whether Axiom will release specifications for various speakers with the port plugs in2. whether the plugs provided by Axiom are completely airtight or whether they provide an aperiodic box alignment3. what the real-world ramifications are regarding extension, sensitivity, power-handling, etc.

1. whether Axiom will release specifications for various speakers with the port plugs in2. whether the plugs provided by Axiom are completely airtight or whether they provide an aperiodic box alignment3. what the real-world ramifications are regarding extension, sensitivity, power-handling, etc.

TAM, thanks very much for sharing your experience.

I first saw port plugs as an option used in HSU subs and later their hybrid equivalents from Outlaw that provided a port plug as an option to give a little more bass extension at the lowest levels. With its usage, however, comes a slight reduction in potential SPL output so I assume the concept is similar in the M100 but only in subs and speakers that are capable of low bass extension otherwise, I don't see much value in them.

I have an Outlaw sub with the optional port plug and tried it both ways and honestly, I couldn't hear much if any difference.

I have an Outlaw sub with the optional port plug and tried it both ways and honestly, I couldn't hear much if any difference.

I too have an Outlaw sub with that port plug option and concur with the above. After numerous tests with and w/o plug the engaged I could not detect any audible difference. Maybe at relatively high SPL levels but for normal listening, no change.

chess: If that was directed to me, I don't do graphs; however, I do know what I hear & prefer...

TAM

You need to be a bit less sensitive there Tam.It was just a general statement that i'd like to see frequency response graphs of plugs in, plugs out to see what kind of difference it makes (with all other variables being equal). I'm sure the good Axiom folk already have such graphs.

_________________________"Those who preach the myths of audio are ignorant of truth."